Abstract: To make an accurate count in filter rod making, a method was proposed based on Canny operator and image processing technology through edge detection of all filter rods in a tray with Canny operator, and by means of the dilation operation in image morphology to increase the definition of the detected edges. At the same time, the positions of filter rods are accurately located according to their circular profiles and further their number is determined. The filter rods of different lengths were counted with the proposed method, the results showed that this method could count the number of filter rods accurately with an accuracy of 99.27%, it also showed good adaptability and robustness capable for counting filter rods of various circumferences. This method provides a technical support for reducing the consumption of filter material.